Fly Ash in

Fly Ash in Concrete

© Perkins+Will, November 2011 PART I: Where Opinions Align on Fly Ash in Concrete

CONTENTS 06 Acknowledgements 18 There Will Be Fly Ash in Our Future “09 Disclaimer 120 Composition of Fly Ash 2 10 Executive Summary 22 Radioactivity and Fly Ash

12 Introduction to Fly Ash “

PART II: Where Opinions Differ on Fly Ash in Concrete

26 Fly Ash as a Waste Product 34 Closing Thoughts 228 Climate Change Impact 36 Appendix – Supplemental Information 30 Resource Stewardship 47 Graphics Index

32 Toxic Burden 48 Glossary of Terms

35 Risk Management 49 General Web Resources

50 End Notes THE PERKINS+WILL TEAM ACKNOWLEDGEMENTS

Authors The authors would like to thank our colleagues at Perkins+Will for sharing their insights Breeze Glazer, LEED™ AP BD+C on fly ash in concrete and especially our Steven Danielpour, Robin Guenther, and Craig Graber, AIA, LEED™ AP BD+C Calvin Smith. They helped us to develop this research idea, but also gave us thoughtful comments on this paper. We would also like to thank Tom Lent from the Healthly Building Carolyn Roose, LEED™ Green Associate Network, Brent Ehrlich from BuildingGreen, publisher of the Environmental Building News Peter Syrett, AIA, LEED™ AP BD+C for being peer reviewers. Lastly, we would like to acknowledge that this report would not have been possible without the support of Peter Busby and Phil Harrison, the co-leaders of Chris Youssef, NCIDQ, LEED™ AP BD+C Perkins+Will’s Sustainable Design Initiative.

Additional Research

Kim Farrah, LEED™ AP ID+C

Graphic Design

Kristina Buller “It’s very complicated…if fly ash is a hazardous waste and it becomes part of a concrete wall, is the wall a hazardous material?”

— Scot Horst, a senior vice president at the U.S. Green Building Council.3 08 FOREWORD

“ combustion wastes should not be able to avoid environmental regulation just because they are destined “Even though millions of tons of for reuse in construction; the coal combustion products are distribution of these products used every year, millions more in homes, schools, and are still going to waste.” roads throughout the nation — Headwater Resources, self-proclaimed to be “America’s largest should not be allowed unless manager and marketer of coal combustion products”1 adequate, independent testing is done to ensure that the increasing usage will not result in increasing exposures to building occupants or construction workers.”

— Public Employees for Environmental Responsibility (PEER) 4 examining its uses in other building products is necessary. a replacement for Portland in concrete, a subsequent paper like to note that while this paper covers only its origins and use as to examining the impact of fly ash in concrete. The authors would topics are worthy of examination, we have chosen to limit our efforts cementitious materials such as blast furnace . While these by-products such as desulfurization or secondary products. This paper does not address other coal combustion fly ash in concrete and does not address fly ash in other building by original scientific research. The scope of this paper is limited to consolidation of publicly available information and is not supported The research for this paper is based on a thorough examination and areas where opinions diverge on the impact of fly ash in concrete. delineates where there is agreement, and the second half covers clarity, we have structured this paper into two halves. The first half facts and minimal independent scientific research on this topic. For paper consolidates the many diverse opinions, mutually agreed upon and ecological implications of using this building material. This professionals in their decision-making processes about the safety We prepared this report to assist building owners and design this very complex topic. Simply stated: there is no clear conclusion. concrete. Rather, this paper is our first attempt to better understand is not to write an endorsement or to rebuke the use of fly ash in to opinions on environmental harm and human safety. Our intent the Hoover Dam, it’s use concrete still has no consensus with regard Eighty-two years after fly ash was first used in the concrete mix of Disclaimer “ material. Flyash,inaway, isstillsolvingasymptom. produce energy, it isagooduseoftheby-products.” of coalasafuelsource.Untilwe findbetterwaysto material. Inanotherwayit’s justifyingtheburning In onesense,yes,you’reusing upthiswaste There aretradeoffstoanything;there’s noperfect — Daniel Hendeen, a research fellow at the University of Minnesota, Center for Sustainable Building Research. 2

09 FOREWORD 10 FOREWORD

Executive Summary the estimated 100 to 500 million tons that have been dumped in United States since the 1920s.6 This equates to 813,462 To power our world, we burn a billion tons of coal every year,5 tons of fly ash disposed of every week. Unfortunately, this “waste” leaving significant quantities of coal ash. Rather than sending this fly ash is not always contained safely. In 2010, 31 coal ash disposal ash to landfills, some is being recycled for beneficial uses, including sites were linked to contaminated groundwater, wetlands, creeks, as an additive or key component of building products. In particular, and rivers in fourteen states.7 the lighter ash (the dust that rises up the flue when coal is burned – usually referred to as fly ash) is now a common ingredient in For the fly ash that is diverted into concrete, there is the concrete, carpet backing, recycled plastic lumber, , acoustic unanswered question. Is fly ash chemically changed when it is ceiling tiles, and myriad of other building materials. mixed into concrete? We were unable to find any studies that prove fly ash is changed chemically when in concrete. There is not Though fly ash has become a ubiquitous ingredient in building scientific consensus on this topic. This is an important question materials over the last 82 years, it has been largely ignored by because fly ash carries the same toxic burden as the coal from regulatory agencies in the United States. That changed in 2010 which it was derived. If the harmful substances in fly ash were when the United States Environment Protection Agency (EPA) rendered harmless when bonded into concrete, this would be one of proposed to classify fly ash as a hazardous material. The EPA the most significant benefits to the use of fly ash, even exceeding actions surprised many design professionals, builders, and owners the value of recycled content. The studies that we found (and are because fly ash had become a common “recycled” component in noted in this paper) have mostly focused on heavy metal buildings. Until the EPA’s proposed regulations, fly ash’s provenance ( in particular) from the concrete, and have not addressed and its life cycle impacts were largely overlooked. the other harmful substances regularly found in fly ash dust generated from modifying or demolishing fly ash concrete, or what Of all the building materials that have fly ash in them, concrete happens at the end of its life in a building. merits special consideration. Foremost, it is a very common beneficial use of a fly ash. Fly ash mixed into concrete accounts Since the production of is estimated to generate for approximately seven percent of the fly ash that is diverted from between two and five percent of the world’s (GHG) landfills each year. The remaining un-diverted fly ash is either emissions,8 3.4 percent according to the EPA,9 the substitution of fly sent to dry or wet disposal facilities. The disposal of fly ash places ash for cement is often cited as a means to reduce footprint. significant stress on our overtaxed waste system. In 2008, 42.3 However, the assertion that replacing Portland cement with fly ash million tons of fly ash were sent to coal ash disposal sites on top of in concrete reduces GHG emissions is only correct if the production about the use of fly ash in concrete: this work has been done, three tough questions remain unanswered in concrete, including the initial production from coal ash. Until and rigorous life-cycle assessment of the embodied energy of fly ash concrete and at end of its life. There also needs to be a complete to address the chemistry of fly ash’s toxic burden when it is in and its use in concrete. At a minimum, research needs to be done a better understanding of the provenance and life-cycle of fly ash a good substitution for Portland cement in concrete, it must have For the building community to continue to have faith in fly ash as harmful by regulatory agencies. be expensive to remove and dispose after they had been deemed are also relevant precedents. All these materials have proven to the most infamous example, but asbestos and -treated wood widespread use before they were deemed hazardous. paint is precedents in the building industry for products that attained of fly ash is still pending. That being said, there are numerous the writing of this paper in the fall of 2010, the EPA regulation material on its use in concrete or other materials is unclear. As of The impact the EPA’s classification of fly ash as a hazardous by weight. footprint than Portland cement when CO CO production of Portland cement produces approximately 1.25 tons of carbon dioxide (CO source of fly ash, generates approximately twenty to thirty tons of of fly ash is not taken into account. The burning of coal, the 2 per ton of ash, 2 11 ) per ton of fly ash generated. meaning fly ash actually has a higher carbon 3 2 1 into ourhomes,schools,hospitals, andoffices? Is itbettertosendflyashlandfills ortodivertit Is flyash’s toxicburden benign wheninconcrete? fly ashisusedinlieuofPortlandcement? What arethetotalGHGemissionsofconcretewhen

2 emissions are compared 10 In contrast, the

11 FOREWORD 12 FOREWORD

Introduction to Fly Ash Portland cement. There are many performance reasons to use fly ash in concrete: it improves plasticity, decreases permeability, The recipe for concrete is simple: a mixture of , Portland increases sulphate resistance and enhances durability. Volcanic ash cement, fine aggregates and course aggregates, cured for 28 days. was used by the ancient Romans in concrete, and fly ash has been Portland cement is the key ingredient in concrete, composing used as a (a material that has cementitious properties) in approximately twelve percent of the mix weight, acting as the modern concrete since the building of the Hoover Dam in 1929.12 binding agent that holds sand and other aggregates together in a Each year in North America, fly ash replaces about eight percent of hard, stone-like mass. This basic recipe for modern concrete has Portland cement in concrete, and in some European countries the been altered countless times since Joseph Aspdin, a bricklayer, replacement rate exceeds 25 percent.13 Reducing or eliminating patented Portland cement in 1824. Today, the concrete mix is Portland cement has resulted in lower levels of extraction for virgin altered to improve compressive strength, to shorten curing time, silica and limestone as well as reducing the GHG emissions tied to improve workability and many other performance traits. the concrete itself; but, as noted previously, current calculations do not take into account the process of fly ash production and instead One of the most unique changes to concrete’s recipe is the use focus on the concrete itself. Recently, fly ash has also been used of fly ash, a by-product from coal-fired power plants, in lieu of to improve the environmental footprint of concrete by lowering the

KNOWN COAL RESERVES

33 – 40 reserves 25 – 32 reserves 17 – 24 reserves 9 – 16 reserves 1 – 8 reserves

Sources: http://www.sourcewatch.org/index.php?title=Existing_U.S._Coal_Plants, http://www.sourcewatch.org/index.php?title=Existing_coal_plants_in_Canada hazards such as lead and mercury. may have trace amounts or even higher levels of known health often contains the harmful elements of the burned coal. Fly ash of concrete. Since fly ash is a by-product of coal combustion, it question of whether it truly improves the environmental performance The fact that fly ash is not a benign material, however, raises the 38 page on Pozzolan” included in Appendix: information and performance standards for fly ash concrete are (LEED™) and other green building standards. Council’s (USGBC) Leadership in Energy & Environmental Design building rating systems such as the United States Green Building the . Its use is also rewarded as recycled content in green potable water content in the mix, thereby diverting fly ash from ELECTRICITY PRODUCTIONBYCOAL 0 –1.9TWh 2 –5.9TWh 6 –7.9TWh 8 –9.9TWh 10+ TWh

. “Technical is Fly a Ash Consideration: 15 Trade organizations such as 14 Additional technical Sources: http://www.eia.gov/cneaf/coal/page/acr/table1.html, http://www.centreforenergy.com/FactsStats power plants. supplemental cementitious materials (SCMs) derived from coal-fired LEED™ for Healthcare also has a credit that limits mercury levels in under their green building rating system, and the recently released has put limits on the mercury content for fly ash in concrete California’s Collaborative for High-Performance Schools (CHPS) coal combustion wastes in building and consumer products.” scientific support for the safety or quantifiable benefits of using the use of fly ash in concrete because there is no “demonstrated Public Employees for Environmental Responsibility (PEER) opposes position has been challenged by risk of entombing toxic compounds into concrete. The pro-fly ash benefits of the “reuse” of fly ash outweigh the potential health Association (ACAA) have taken the position that the environmental the American Concrete Institute (ACI) and the American Coal Ash many environmental groups. 16

13 FOREWORD 14 FOREWORD

THE LIFECYCLE OF FLY ASH

coal combustion

extraction

power plant coal (electrical utility)

DISPOSAL

landfill “dry” “wet”

discharge

end of end of product concrete lifecycle lifecycle

demolition construction ash marketer (aggregator) fly ash in concrete concrete batch plant batch concrete BENEFICIAL USE fly ash soil amendment manufacturing fly ash in consumer and building products building

15 FOREWORD

PART I:

Where Opinions Align 1on Fly Ash in Concrete 18 PART I: WHERE OPINIONS ALIGN

There Will Be More Fly Ash in Our Future

In 2006, the U.S. produced approximately 227 gigawatts of electricity from coal, about 25.7 percent of the world’s supply of coal-fired electricity.17 The majority of the 615 coal-fired power plants in the United States are clustered in parts of the Midwestern, Mid-Atlantic and Southern United States, with less than ten in New England and only five in the Pacific Northwest.18 Pennsylvania the country with 40 coal plants, and Ohio is a close second with 35.

DEPENDENCE ON COAL FOR ELECTRICITY BY COUNTRY:

South Africa 93% The pending EPA hazardous Australia 77% material ruling has generated Israel 63% a great deal of debate on

Greece 52% the environmental traits of

Poland 92% fly ash. In this debate, we

Kazakhstan 70% found that opinions are not

Czech Republic 60% completely divided; there

USA 49% is general consensus on fly ash’s growing market share, PR China 79% chemical composition and 69% radiological risk. Morocco 55%

Germany 46%

00% 20% 40% 60% 80% 100%

Coal Dependency Outside of the United States, coal is also a common source fuel for electrical generation. Coal-fired power plants currently fuel American electric utilities and other power producers generate 41 percent of global electricity. In some countries coal is the 136 million tons of fly ash and other coal combustion residuals primary source of electricity. Due to its relatively low cost, the (CCRs), which include , slag and flue gas use of coal as a source fuel for electrical generation worldwide

desulfurization (FGD) material (sulfur dioxide (SO2)) exhaust will likely continue to grow. It is estimated that coal will fuel matter. FGD is commonly used as a replacement for mined 44 percent of global electricity needs in 2030.22 As coal will gypsum in “synthetic” gypsum wallboard).19 Of the coal burned continue to be a global energy source for the foreseeable future, in United States power plants, about ten percent ends up as a it is a safe assumption that the coal industry and others will combination of fly ash and bottom ash.20 Forty percent of this continue to seek uses of fly ash. ash is “re-used.”21 CONCRETE CONCRETE Source: Making Better Concrete: Guidelines to Using Fly Ash for Higher Quality, Eco-Friendly Structures by Bruce King. (Portland cement) silicates silicates calcium the Above All of CS WITH WITHOUT

FLY ASH + + FLY ASH (extracted from water) from (extracted hydrogen hydrogen (fly ash) (fly silica silica Si H

= = hydrate hydrate calcium silicate silicate calcium calcium silicate silicate calcium hydrate hydrate CSH CSH (MORE glue) (MORE (glue) + ash-1-600.html images/ccbs/gallery-ccbs/pages/Class-F-fly- Source: http://www.caer.uky.edu/kyasheducation/ magnification. viewed via SEM at 2000x Class Ffly ash sample as (weak crystals) calcium Copyright UKCAER. CH

19 PART I: ALIGN 20 PART I: WHERE OPINIONS ALIGN

Composition of Fly Ash Additional information on performance and technical aspects of fly ash in concrete are included in Appendix: “Summary of Current As noted earlier, fly ash is part of coal ash, or the “total residue,” Regulations, Codes and Technical Standards” on page 40. created during the combustion of coal in electrical power plants. The coal that is not incinerated either settles at the bottom of the Fly ash contains many hazardous substances within its composition

boiler (“bottom ash”) or rises in the flue (“fly ash”). In short, fly ash in addition to substantial amounts of (SiO2) and is the dust collected in the smokestacks as a result of combustion. (CaO). The composition of both Class C and F fly ash varies greatly, but may include “one or more of the following Depending on the source and properties of the coal being burned, elements or substances in quantities from trace amounts to the components of fly ash vary considerably, but all fly ash includes several percent: arsenic, , , , ,

substantial amounts of silicon dioxide (SiO2) and calcium oxide or chlorine, , lead, , mercury, , , lime (CaO). The two types of fly ash used in concrete are categorized , , and , along with dioxins and Polycyclic as either Class C or Class F by the American Society for Testing aromatic hydrocarbons PAH compounds.”24, 25 (It is important to note and Materials (ASTM) under their C618 standard.” The primary the scientific community’s consensus on the toxicity of fly ash as a difference between these classes is the amount of calcium, silica, raw material.) alumina and content in the ash. The most commonly produced fly ash, Class F, exhibits calcium oxide (CaO) contents below All of the chemicals listed above are cited on government watch lists eighteen percent and often well under ten percent. In addition to as substances that have known and suspected impacts on human higher alkali and (SO4) contents, Class C fly ash has a lime health. For instance, according to the EPA, mercury is a known (CaO) content of more than ten percent, and therefore is often persistent bioaccumulative toxin (PBT), and it is a developmental referred to as “high calcium” fly ash. Class C fly ash has enough toxicant under California’s Proposition 65.26 Mercury is also calcium to exhibit cementitious properties by itself, necessitating implicated or suspected to be the following; the organizations only water to hydrate and harden. or noted authors associated with these positions are listed in parentheses:27 As noted in the introduction, the chemical properties of the fly ash are largely influenced by the chemical content of the type • Cardiovascular or blood toxicant (KLAA) of coal burned (i.e., , bituminous, sub-bituminous and • Endocrine toxicant (IL-EPA; KEIT; WWF) ). Class F fly ash is created when harder, “older” anthracite • Gastrointestinal or liver toxicant (RTECS; STAC) and is burned. Class C is produced from burning • Immunotoxicant (HAZMAP; SNCI) “younger” lignite, which is mostly found in the Western United • Kidney toxicant (HAZMAP; KLAA; LAND; MERCK; STAC) States. Regional proximity is the primary reason one type of fly ash • Neurotoxicant (ATSDR; DAN; EPA-HEN; EPA-SARA; FELD; HAZMAP; KLAA; is specified over another. In general, Class F fly ash is typically OEHHA-CREL; RTECS; STAC) used to partially replace Portland cement in concrete because it • Reproductive toxicant (EPA-SARA; FRAZIER; HAZMAP; OEHHA-AREL) is superior to Class C in mitigating both sulfate and alkali–silica • Respiratory toxicant (HAZMAP; NEME) damage, but concrete can be made with Class C fly ash without any • Skin or sense organ toxicant (HAZMAP; KLAA; RTECS) Portland cement. Additionally, it is critical to note that “because of variations in the chemical structure of coal from different regions, it’s See Appendix: “Body Burden of Substances in Fly Ash via Government often easier to remove mercury from eastern coal than western coal. Watch List” on page 44 for more information on the suspected and known Also, because eastern coal usually has a higher heat rate, there is less health impacts of the substances found in fly ash. mercury per unit of energy in eastern coal than from western coal.” 23 Fly ash contains approximately one part per million of mercury. To put this quantity in perspective, this exceeds, by a factor of 1000, the maximum level of mercury in permitted by the EPA, which is two parts per billion. It only takes 1/70th of a teaspoon of mercury to contaminate a 20-acre body of water and make all fish within it toxic to humans. This is about the amount of mercury in a

typical medical thermometer.28 generator coal pulverizer coal bottom ash steam boiler COAL FUELEDPOWERPLANTPROCESS (electrical utility) (electrical plant power stack fly ash precipitator electrostatic

21 PART I: ALIGN 22 PART I: WHERE OPINIONS ALIGN

Radioactivity and Fly Ash Radioactive elements in coal remain after combustion and are held in both bottom ash and fly ash. In particular, most of the With a few exceptions, consensus among the scientific community and are released during combustion from the original coal says that use of fly ash in concrete does not constitute a and are distributed between the gas and solid combustion products. significantly different radiation risk than the Portland cement it The partitioning between gas and solid is controlled by the volatility replaces. Both Portland cement and fly ash pose a radiation risk and chemistry of the individual elements. For example, virtually similar to that of common soil. 100 percent of radon present in coal is lost in stack emissions. In contrast, less volatile elements such as thorium, uranium, and the Coal is largely composed of organic matter, but some of the majority of their decay products are almost entirely retained in the inorganic matter (the trace elements) in coal is radioactive. These solid combustion wastes.29 radioactive trace elements include uranium (U), thorium (Th), and their numerous decay products, including (Ra) and In fly ash, the uranium is more concentrated in the finer sized radon (Rn). Although these elements are less chemically toxic particles. During combustion of coal, uranium is concentrated than other coal constituents such as arsenic, selenium or mercury, on ash surfaces as a condensate, This surface-bound uranium is questions have been raised concerning possible risk from radioactive potentially more susceptible to leaching. The radioactive elements coal’s combustion by-products being used in consumer products. from coal and fly ash may come in contact with the general See graphics of consumer, building products, and agriculture public when they are dispersed in air and water or are included in applications that contain fly ash in Appendix: “Coal Combustion commercial products that contain fly ash.30 Wastes in Our Lives” on page 45. radiation resulting from fly ash stating: Guideline for Federal Procurement,” also discusses the potential A 1983 EPA document, “Cement and Concrete Containing Fly Ash; uranium in fly ash in the 1990s, notes that: United States Geological Survey (USGS) who oversaw research on Robert Finkelman, a former coordinator of coal quality with the concentrated up to ten times their original levels. Nevertheless, when coal is burned to create ash, the uranium and thorium are Trace amounts of uranium and thorium occur naturally in coal, but “ to miners.” and other elements in coal might only form a genuine health risk of total exposure. Radiation from uranium amount of background radiation, probably less than 0.1 percent [F]or the average person the by-product accounts for a miniscule 31 IS FLY ASHINTHISROOM? “ different from the radiation risk posed by common soil.” from the cement it replaces and neither of these is significantly constitute a significantly different radiation risk than the risk that the use of typically-occurring fly ash in concrete does not a decreased radon exposure. In light of this, the EPA believes this small increase in gamma exposure is likely to be offset by average, result in a small increase in gamma radiation exposure, concentration. Thus, while fly ash use in cement would, on the concrete is only a few percent compared to the absolute radium emanation rate of fly ash in its raw state and as used in Tests recently conducted for EPA substantiate that the radon

23 PART I: ALIGN

PART II:

Where Opinions Differ 2on Fly Ash in Concrete 26 PART II: WHERE OPINIONS DIFFER

water is transported to an ash pond. Many of these ash ponds are Opinions differ widely on the environmental and health impacts not lined, increasing the probability of seepage and leaching of of using fly ash in concrete, specifically, and other building contaminants into groundwater as well as runoff into surface .

products, additionally. These debates center around the C02 impact of substituting fly ash for Portland cement, regional Conversely, while more costly, the dry collection method reduces limitations and resource stewardship, whether the toxic burden the potential for pollution while increasing the potential beneficial of fly ash is actually “encapsulated” in the concrete mix, and uses of the fly ash. Dry ash sites should also be lined--although the inherit risks of putting fly ash into our buildings. many are not--and should be stabilized with vegetation to minimize environmental damage caused by wind .

In 2008, 42.3 million tons were landfilled, compounding the Fly Ash as a Waste Product / estimated 100 to 500 million tons already been stockpiled in Handling and Disposal of Fly Ash United States landfills since the 1920s.40

After fly ash is produced in coal power plants, it and other Coal The storage and handling of fly ash became an issue of national Combustion Residue (CCRs) await two possible fates: recycling or prominence in December 2008 with the collapse of an disposal. Only about 25 percent of all fly ash produced is diverted at an impoundment for wet storage of fly ash at the Valley annually. The remainder is discarded in engineered landfills and Authority’s (TVA) Kingston Plant. The cleanup is projected to cost surface impoundments or abandoned mines and .32 Not $268 million and take up to four years to complete. According to everybody believes that the redirecting of fly ash from disposal sites the EPA as of May 2010,

The magnitude of the fly ash disposal issue is enormous. CCRs represent the second largest industrial waste stream in the United

States after .34

is beneficial. Public Employees for Environmental Responsibility “Drinking water, river water and groundwater in the area are (PEER) has been one of the most vocal critics of recycling. Following sampled on a routine basis and current results indicate no PEER’s August 2010 statements, fly ash has no “demonstrated exceedances [SIC] of drinking water standards or surface water scientific support for the safety or quantifiable benefits of using coal quality criteria. Semiannual sampling of groundwater wells combustion wastes in building and consumer products.”33 indicates no contaminant plume is present under or around the site.”41 The disposal issue cannot be ignored. Such large quantities of CCRs are generated each year in electric utility plants, they have become Fly ash exists in four primary forms based upon its intended end the third most abundant mineral resource in the United States.35 use: dry, conditioned, stockpiled and lagooned. When transported In 2008, electric utilities and other power producers in the United to project sites for use in concrete, it most often is in the dry form, States generated 136 million tons of fly ash and other CCRs, which whereas it is most often stored for long term in wet or moist form. also include bottom ash, boiler slag and flue gas desulfurization Some agencies such as the TVA are moving from wet to dry storage (FGD) material. Of the coal burned in United States power plants, to avoid future spillage. about ten percent ends up as a combination of fly ash and bottom ash, according to the American Coal Ash Association (ACAA).36 Of This transition also has health impacts since the dry application of that ten percent, only about 40 percent is diverted to beneficial uses fly ash may pose danger prior to encapsulation in concrete. During leaving 60 percent destined for disposal.37 Globally, the utilization dry storage, fly ash can be blown by the wind, become airborne and rate of fly ash is much lower, around 25 percent.38 eventually be released into the greater environment. According to a 2010 Greenpeace report, Disposal takes place using one of two methods, and both types of facilities are typically located near electric utilities. CCRs are “about twenty percent of coal ash particles are hollow, making either dumped in dry form into one of approximately 300 landfills them easily dispersible by wind. Regardless of whether dry or wet in the United States, or they are contained in wet form in one of disposal methods are used, without a properly enclosed storage approximately 580 surface impoundments, also known as “ash ponds.”39 In the wet disposal method, a slurry of CCRs mixed with Source: American Coal Ash Association, annual survey data calendar 2000 2004 2006 2003 2009 2002 2005 2007 2008 1980 1990 2001 1985 1995 1970 1975 year

(million tons) (million generated generated fly ash ash fly 48.3 48.3 54.2 63.0 42.3 26.5 70.2 70.8 68.1 72.4 63.1 72.4 76.5 49.0 71.7 71.1 fly ash ash fly 44.2% 30.8% 40.9% 34.9% 38.6% 39.2% 25.0% 44.7% 13.3% 23.5% 25.5% 32.4% 39.7% 10.6% 41.6% used 8.3% (%)

disposed 2005 2006 2007 2008 2009 60.8% 60.3% 55.8% 55.3% 69.2% 75.0% 86.7% 58.4% 89.4% 76.5% 74.5% 61.4% 91.7% 65.1% 67.6% 59.1% fly ash ash fly (%)

WASTE DISPOSALVOLUME THE U.S.IN2008 FLY ASHUSEDIN TONS MILLION amount of fly ash in the waste steam today: The approximate approximate The MILLION TONS FLY ASHDISPOSED BENEFICIAL USE DISPOSAL more and more is piled …only asmall amount of fly ash is recovered N 2008 IN on each year… and reused and TONS MILLION

27 PART II: DIFFER 28 PART II: WHERE OPINIONS DIFFER

system, coal ash can easily be scattered into the atmosphere as grinding or jack hammering concrete, or in places that crush it for secondary dust pollution. This will have serious consequences for recycling at the end of its lifecycle.44 The presence of fly ash in the people living downwind of the coal ash impoundment.”42 concrete matrix could also significantly increase the hazards posed by exposure to concrete dust. During fabrication and construction of concrete, workers may have direct contact with the concrete mix both in the mixing plant and Given the risks of disposal, inadequate precautions taken at many when concrete is poured into the . This exposure takes disposal facilities, and the potential for catastrophic failures, place before any chemical binding occurs, meaning the toxic significant environmental benefits may be gained by diverting fly burden of the fly ash is “free” and not yet “bonded” within the ash from disposal and using it in concrete as long as that process concrete, an occupational exposure with significant consequences. can be done safely, protecting both the public and the environment. In addition to the fly ash’s harmful substances derived from the Conversely, other means could achieve a similar outcome through coal itself, fly ash may also absorb ammonia or ammonium sulfate tighter regulations and enforcement of more adequate disposal compounds when the fly ash is “conditioned” in the flue. According facilities; however, these require political change and the will to to Paradise, Petechuk, and Mertz “during the mixing and pouring of enforce the regulations, while the former approach is within the concrete, ashes with high amounts of ammonia may create harmful sphere of influence of the design and construction community. odors that can affect workers’ health.”43 Another time of potential exposure is during dust-generating modifications or demolition Of the 136 million annual tons of total CCRs cited earlier, currently of concrete. As previously noted, in order to confirm fly ash’s only 12.5 million tons (or nine percent) represent fly ash used in safe use, peer-reviewed studies are needed to prove that fly ash’s concrete; this total figure includes all CCRs, including bottom ash, toxic compounds can be trapped in the concrete matrix structure. boiler slag and FGD material. Maximizing the use of fly ash and Furthermore, encapsulation and human exposure needs scientific minimizing the negative impacts of its disposal appear to have analysis to determine what happens with regard to polishing, drilling significant room for improvement. or chipping concrete containing fly ash. No available studies assess the potential occupational exposures in facilities or in jobs involving supported by peer reviewed research.” wastes that may become a later source of pollution… the EPA should immediately halt this marketing program until it has set toxicity standards Ruch of Public Employees for Environmental Responsibility (PEER). He notes “ironically, ‘green’ rating systems give extra credit for using coal of the larger environmental issues surrounding coal’s use as an energy source. One of the most outspoken critics is the Executive Director Jeff rating system.” rating system, “however, if [the] EPA designates fly ash as a hazardous waste, LEED™ committees will take a look at (and re-evaluate) the sure there is alignment around the beneficial use of fly ash,” says Scot Horst, senior vice president in charge of the LEED™ green building for fly ash is contingent on its not being classified as a hazardous material. “We respect EPA’s ability and role as a regulator … and are quite attitudes at the USGBC. As stated earlier, LEED™ for Healthcare addresses the toxicity of fly ash and the USGBC has stated that their support which contributes towards achievement of LEED™ points under the Materials and Resources category. However, there are signs of changing rating system. The replacement of Portland cement with fly ash in concrete is considered a post-industrial (pre-consumer) recycled material, In thismanner, theuseofflyashinconcretehasbeenrebranded asasustainablebuildingpracticethatisprominentlysupportedbytheLEED™ remains conflicted on the environmental impact of fly ash, as indicated by their proclaimed reevaluation of the material. use of coal ash in concrete and concrete-like products does not cause a threat to human health and the environment.” includes a link to a Dow Jones Newswire story quoting EPA Administrator Lisa Jackson as saying “there seems to be genuine agreement that the rebranding is best exemplified by the “America’s Energy” website, which is a part of the coal industry’s “Clean Coal” campaign. This website of fly ash actually supports the coal industry by partially absolving it of accountability for the coal combustion processes and outputs. This promotes fly ash as “recycled” and benign as a part of an attempt to rebrand the industry as “green.” In fact, some critics allege that the use words, producers have been able to reduce the cost of disposal by selling their waste as a “recycled” commodity. The coal industry heavily financial incentive for diversion, as diversion reduces the substantial costs associated with the safe storage and disposal of fly ash. In other and application of the LEED™ rating system. rate increase from 30 percent to 40 percent and is clear evidence of the strong growth in the green building movement in the United States More than 1.1 billion tons of fly ash were produced in the last ten years, and 420 million tons have been recycled. Concern about Rebranding of a Waste Product 48 Others take a harder line than the USGBC, and have decried the use of fly ash in concrete or other building materials because 49 46 The ACAA’s claim that fly ash is the second largest waste stream clearly identifies the potential 45 This reflects a diversion 47 As noted, the EPA itself

29 PART II: DIFFER 30 PART II: WHERE OPINIONS DIFFER

Climate Change Impact The editors of Environmental Building News (EBN) have also suggested that significant environmental benefits can be gained Concrete is the most ubiquitous construction material in the by substituting fly ash for Portland cement because it reduces the world; current average consumption is approximately one metric overall embodied energy and carbon footprint of concrete. This ton installed per year for every person on the planet.50 The endorsement does not include instances where fly ash serves only manufacturing of concrete is very intensive, from the extraction of as a “filler,” as in carpet backing.56 Though somewhat self-evident, all concrete’s raw materials through transportation to the site. The one important note is that fly ash can reduce the carbon footprint manufacturing of Portland cement is especially energy intensive. To of concrete only if it displaces the Portland cement, not as an put this in perspective, for every 1000 kg (2205 lbs) of Portland augmentation to the mix. cement produced in the United States, 927 kg (2044 lbs) of 51 CO2 are emitted. Any action that reduces the carbon footprint Environmental organizations such as the Environmental Integrity

of concrete, therefore, can make a real dent in overall global CO2 Project (EIP), Public Employees for Environmental Responsibility

emissions. Of the total CO2 emissions related to concrete, including (PEER), Stockholm Environment Institute and Earthjustice,

those from manufacturing, transportation and placement, the however, dispute the overall reduction of CO2 emissions associated primary culprit is Portland cement, accounting for about 80 percent with substituting fly ash for Portland cement. Foremost, these of total emissions. Production of Portland cement is especially organizations note that “creating coal ash generates huge amounts 57 carbon intensive because it emits CO2 not only from burning fossil of climate altering greenhouse gases,” which are not taken into fuels to heat the kilns, but also as a direct by-product of the account by the EPA nor by trade associations. Coal-fired power, “calcining” process that transforms the limestone raw material into which creates fly ash, is a main source of greenhouse gases in

calcium oxide (lime) and CO2. While substituting fly ash for Portland the United States and it is now estimated that coal accounts for cement has a positive impact on GHG emissions in concrete approximately a fifth of global GHG emissions.58 “If the federal production, the source emissions associated with coal combustion government is truly going to reduce its carbon footprint, banning are not yet accounted for because they are considered external to coal ash is an unavoidable step,” according to PEER Executive the concrete production. This lifecycle cost analysis approach is the Director, Jeff Ruch.59 PEER also claims that the EPA overestimated source of the differing opinions regarding the total climate change the energy savings associated with recycling fly ash in cement kilns impacts associated with the use of fly ash. in the recently proposed coal ash regulations. As noted above, the EPA estimated that diverting fly ash to cement kilns saves The concrete industry and the EPA have argued that the substitution $4.9 billion in energy costs, “but the Agency’s Office of Air and

of fly ash for Portland cement can have a significant benefit in CO2 Radiation, in analysis developed to support the separate and more emission reduction: far-reaching Clean Air Act standards, estimated total energy costs for the entire industry at no more than $1.7 billion.”60 • According to the American Concrete Institute (ACI) in their

analysis of CO2 emissions for concrete that substituting fly ash for 25 percent of Portland cement in a typical concrete mix can 53 reduce overall CO2 emissions by thirteen to fifteen percent.

• The American Coal Ash Association (ACAA) estimates that fly ash in concrete is responsible for avoiding twelve million tons of 54 CO2 emissions each year.

• The EPA’s Office of Air Quality Planning and Standards (OAQPS) estimated that recycling fly ash in cement kilns saves $4.9 billion in energy costs annually.55

Amongst building materials, Portland cement has a very high

embodied energy and is by far the largest single emitter of CO2 in

the U.S., responsible for two percent of total CO2 emissions and five

52 percent of all human-caused CO2 emissions worldwide. Sources: World Business Council for and Pew Center on Global Climate Change. of the world’s total is responsible for responsible is Portland Cement Portland GREENHOUSE GAS(GHG) GHG emissions emissions GHG Manufacturing EMISSIONS

GHG emissions emissions GHG of the world’s total for responsible is Combustion Coal

often overlooked when calculating the environmental benefits of fly destined for concrete are also a matter of some debate and are The impacts associated with storage and transportation of fly ash Transportation Impacts Geographic Availability and been destroyed from strip mining. to halfofthestateRhodeIslandand1,000milesstreamshave underground mines. In West Virginia alone, woodlands equal in size States coal is extracted in surface mines; the rest comes from processing operations for coal. Approximately 60 percent of United benefits need to be weighed against the mining, extraction and key reason to use fly ash as a replacement. Opponents note these processing operations in the production of Portland cement as a environmental benefit of reduced impact of mining, extracting, and Proponents for the use of fly ash in concrete often cite the Resource Stewardship given power plant. it varies based on the specific type of coal and the technology of a geography and economics govern the chemical content of fly ash as outweighed by greater carbon intensity from transportation. Regional by substituting Portland cement for fly ash may be negated or distances to the site, and the carbon dioxide reduction provided understand that the fly ash he specified must travel considerable sense. For example, a project manager in the Middle East should availability informs where the use of fly ash makes the most America and Africa have considerably fewer reserves. Geographic and Europe are rich in the resource, whereas the Middle East, South Coal is not distributed evenly across the world. North America, Asia become prohibitive. is about 50 miles, beyond which the transportation costs start to of Florida found that the de facto distance from plant to project a larger issue. Life cycle analysis by researchers at the University appropriate for use in concrete, then storage and transport become not located near coal-burning power plants that produce fly ash like Nevada with only three coal power plants. burning power plants, while other states have much less reliance, project. As of 2005, Pennsylvania has been the leader with 40 coal implications on the environmental effects of fly ash for a particular distribution of coal-burning power plants in the United States has coal, with the exception of Rhode Island and Vermont, and such ash use. Forty-eight states produce at least some electricity from 63 61 62 If a project is

31 PART II: DIFFER 32 PART II: WHERE OPINIONS DIFFER

Toxic Burden in this application as to be almost nonexistent. It is not possible through conducting leaching tests of raw fly ash to estimate the It is a commonly held belief that the toxic burden of fly ash is leaching, if any, which would take place in a concrete containing rendered “harmless” when in concrete. As Michel de Spot of the fly ash.” EcoSmart Foundation stated, the toxic burden “gets embedded into the concrete matrix the same way that combining two very This is significant because it appears to be the genesis of the idea toxic elements like sodium and chloride creates table salt.”64 The that the hazardous burden of fly ash is held in the concrete and proposed 2010 EPA fly ash regulations, however, have ignited new does not pose a health hazard. We could not, however, locate any debates around the long-term health and environmental impacts of objective scientific analysis that can support any of these claims its use in concrete. made by the EPA.

The toxicity of fly ash while in concrete is in question, not the The document does not discuss the potential health impacts during isolated substance prior to encapsulation; this distinction is all phases of the concrete life cycle, both before and after the final important as the toxicity of fly ash has been scientifically proven. encapsulation of fly ash in concrete. Processes such as handling and Coal ash includes 36 elements and a wide array of potentially toxic mixing fly ash into the concrete mix, grinding, drilling or sanding of constituents, such as aluminum, arsenic, beryllium, cadmium, lead, the finished concrete product, and final demolition or disposal at the manganese, , sulfate and thallium, among others.65 The vast end of the building life cycle are not discussed. It does not appear majority of these substances have substantial negative health effects that any scientific analyses have been conducted on the health and many of them are known according to government and environmental impacts for these instances where the final regulatory bodies in the US (see Appendix: “Body Burden of encapsulated concrete product is physically altered in some manner. Substances in Fly Ash via Government Watch List” on page 44 for additional information). Scientific analysis on the toxicity of Additional studies done since the EPA released its findings in 1983 fly ash encapsulated in concrete, however, is scant. One reason is show little leaching of hazardous substances from concrete with that the chemical composition of fly ash can vary widely depending fly ash, but the academic research is clearly nascent and, as noted on the geological characteristics of the coal at extraction and the prior, very limited. These early studies primarily address the leaching design of the power plant where it is burned. Another reason is the of , but do not evaluate all of the toxic substances complexity of isolating a health and environmental problem back found in fly ash. In general, the key peer-reviewed studies conducted to a single building material: concrete with fly ash. Because we are to date indicate that concrete seems to bind well with some heavy exposed to so many chemicals from so many sources each day, it is metals and that fly ash may help in that process.66 To this point, nearly impossible to isolate and quantify the impact of one chemical in their 2010 report on the environmental impacts of concrete and from a building material such as mercury in a fly ash concrete mix. cement, Environmental Building News cited these key studies on hazardous substances in fly ash concrete: The first instance of government discussion of potential health issues of fly ash is a 1983 EPA document, “Cement and Concrete A 1997 study conducted in Germany by Hohberg and Schiessl Containing Fly Ash; Guideline for Federal Procurement.” This indicating that leaching of heavy metals from concrete products document recognizes the toxicity of substances contained in fly (with or without fly ash) was not dependent of the amount of those ash, but does not put forth any conclusive data that fly ash when metals in the cement.67 used in concrete does not leach hazardous materials. Rather than considering the composite product’s toxicity in isolation, the A 2008 study by researchers at Ohio State University that found document considers the toxicity of fly ash by itself in relation to its when fly ash concrete is exposed to heat through steam curing it encapsulation in concrete: retained 99 percent of its mercury content.68

“The permeability of concrete containing fly ash is negligible A 2009 follow-up study at Ohio State found gas emissions and compared to the permeability of fly ash as typically disposed. liquid leaching of mercury from fly ash concrete was independent of This reduced permeability prevents water or other liquids from the amount of mercury in the cement.69 penetrating concrete and providing a leaching medium through which contaminants could travel.” In contrast to the studies above, a 2004 study by researchers from several universities in China and Japan showed that heavy metals The document also claims that when used in concrete, fly ash do leach from cement mortars and solidified fly ashes.70 Other becomes an integral part of the final product: observations from the study concluded that both Portland cement and fly ash contain a certain amount of heavy and toxic metals; “The surface area of individual fly ash particles, from which leaching is also noted to intensify when the fly ash and water to leaching of trace constituents takes place, is so greatly reduced cement ratio is increased. In addition, these results also show that Portland cement. concrete and the health impacts of using fly ash as a supplement for More research needs to be completed surrounding the chemistry of may also occur in Portland cement at higher levels than in fly ash. ash may be a part of a larger problem: those same contaminants contamination of concrete with mercury and other toxins in coal fly Finally, it is important to note that the recent concerns about the may have fundamentally different physical and chemical properties. because this type of cystraline structure is stronger and, therefore, for our understanding of chemistry of concrete. noted, MIT’s cement “DNA” work is an important breakthrough and Engineering Department. said Professor Sidney Yip of MIT’s Department of Nuclear Science hydrate and we hope the scientific community will work with it,” toward a consistent model of the molecular structure of cement frozen liquids such as ice. “We believe this work is a first step crystalline structures and some with the amorphous structure of crystal, but rather a hybrid that shares some characteristics with at MIT found that the calcium-silica-hydrate in cement is not a molecules mixed with tidy layers of calcium oxide. The researchers geometry consisting of layers of long chains of three-armed silica rare mineral tobermorite (a calcium silicate hydrate) with its ordered hydrate (or calcium-silica-hydrate) resembled the structure of the the MIT study, it was believed that at the atomic level, cement researchers at Massachusetts Institute of Technology (MIT). Until of the cement molecule was only recently decoded in 2009 by concrete’s complex crystalline structure. Surprisingly, the “DNA” should be aligned with a new understanding of the true nature of The research to date on how toxic chemicals are “held” in concrete perform in concrete will differ from coal plant to coal plant. in different fly ashes.” ash and result in different leachability of the same heavy metal, but crystalline phase, particle size, surface structure and reactivity of fly great influence on the chemical, mineral compositions, content of condition of coal in furnace and capturing method of fly ash have Most importantly they note “the source of coal, combustion condition of concrete. the reduced leachability of most heavy metals under the high pH because of diffusion, the fixation effect of cement hydrates, and part of the concrete specimen require much more time to leach surface layers of the concrete specimens. The metals in the inner during testing, the leaching of heavy metals only occur from the 71 72

The factors that govern how heavy metals 73 As Brent Ehrlich of EBN recently 74 This is important 75

Numerous other precedents in the building industry illustrate the EPA’s own history documents several historic precedents should be considered, too. For example, determination of risk is reliant on the future ruling by the EPA, but building products has generated much discussion. The ultimate of fly ash last year, the potential risks of specifying fly ash Since the EPA announced that it was considering the regulation Risk Management the pending EPA ruling when they specified that specific concrete? before it is classified as a hazard, especially if they were aware of a design professional be deemed negligent if they specified fly ash performance. If fly ash is classified hazardous by the EPA, would The standard of care is a part of tort law, centering on negligent the mannerinwhichthoseservicesareperformed(standardofcare). services as delineated in their contract (contractual standard) and is measured in two ways: the professional is required to perform the Architects (AIA), the performance of a licensed design professional issue of “standard of care.” According to the American Institute of in the near future, be considered a hazardous material raises the For architects and engineers, continued use of a material that may, hazardous. products that attained widespread use before they were deemed “’ the chromium and wood as originally presumed.” aquifers. It turns out that the arsenic was not as well bound to arsenic-treated wood in unlined landfills was threatening Florida’s the chemicals in the product. By the mid-1990s, leaching from waste disposal regulations that would typically have applied to 1982, the agency exempted arsenic-treated wood from hazardous guarantee that toxic chemicals remain bound as predicted. In widespread acceptance’ of chemicals in building products is no 76

33 PART II: DIFFER 34 APPENDIXCLOSING THOUGHTS

Closing Thoughts

Fly ash is a piece of the much larger environmental puzzle of using coal as a source of power. Nevertheless, the world’s dependence Exxon Valdez Oil Spill: on coal is growing. In 2009, China alone produced more than 11,000,000 gallons (.13 of an oil super-tanker) 375 million tons of coal ash (fly and bottom ash), enough to fill one average swimming pool every two and a half minutes.77 This ugly reality forces architects to consider the options of the best way to dispose of fly ash. Unfortunately, a good, “right,” or even clear answer to this question is not available. Like many ecological problems we face today, the dilemma is very complex, and the choices involve multiple trade-offs.

Fundamentally, the disposal of fly ash comes down to two different disposal models: dispersed versus centralized. Under a centralized TVA Kingston Power Plant Coal Ash Spill: disposal model, coal fly ash, scrubber sludge, bottom ash, and 1,000,000,000 gallons (11.96 super-tankers, other coal combustion waste by-products are sent to landfills or water and coal combustion combined) held in large disposal ponds. Ideally, under this model, the hazards of coal ash can be regulated and controlled (or at least regulated). Unfortunately, in our current world, the disposal of coal ash is not adequately controlled. A 2010 report on 31 coal disposal sites found that coal ash had contaminated groundwater, wetlands, creeks and rivers in fourteen states including Delaware, Florida, , Indiana, Maryland, Michigan, Montana, Nevada, New Mexico, , South Carolina, Tennessee, Pennsylvania and West Virginia.78 Sometimes, the ecological damage is undeniably evident as seen in the 2008 collapse of one of the retaining walls at the Tennessee Valley Authority‘s Kingston power plant that released over 1 billion gallons (3.7 million cubic meters) of water and coal combustion, affecting an area greater than the 1989 Exxon Valdez oil spill.79

The second disposal approach is to redirect fly ash from disposal sites to “safer” uses, including as a substitute for Portland cement in concrete. Under this model, fly ash is “recycled” into a viable building product, thereby distributing the fly ash into our homes, schools, hospitals and office buildings and, theoretically, holding the fly ash in the concrete mix. Regrettably, our limited knowledge of how concrete binds to the toxic elements in fly ash does not empirically show that the toxic burden of fly ash can be permanently bonded in the concrete mix. This leads to a vexing question: have designers brought another hazardous material inside buildings much like they had done before with lead and asbestos?

EXXON VALDEZ OIL SPILL VS. TVA’S KINGSTON POWER PLANT COAL ASH POND LEVEE BREAK or eventually sent to a landfill. a potential health risk when it is finished and polished, demolished, safely for the life of the concrete matrix or if it will continue to pose We still do not know if the toxic components of fly ash are “held” ash) is one of the largest sources of CO cement, but we also know that coal combustion (the source of fly of concrete are reduced when fly ash is used in lieu of Portland virgin materials needed for concrete. We know the CO material, but, when used in concrete, fly ash reduces the use of environmental consequences. We know that fly ash is not a benign We know that disposing of fly ash in landfills is problematic and has new problem of disposing potentially contaminated concrete? 50 years, the typical building lifespan. Will future generations face a we faced today; however, we may be just putting off the problem for “diversion” of fly ash into concrete may help to solve a problem that in buildings, is it not a hazard when the building is demolished? The If fly ash in concrete is empirically proven to pose no hazard when 2 emissions. 2 emissions

35 CLOSINGAPPENDIX THOUGHTS

APPENDIX:

ASupplemental Information 38 APPENDIX

Technical Consideration: Foremost, when fly ash is added into the concrete, the workability of the mix is improved during pouring. This is due to the spherical Fly Ash is a Pozzolan shape of its particles. Fly ash in the mix allows concrete to flow and pump better than 100% Portland cement concrete. Additionally, Fly ash is one of several supplementary cementitious materials there is the environment benefit that the improved workability can (SCMs) that reacts with substances in the concrete mix to form be achieved with less water. The amount of water in the mix is cementitious compounds. As a result, fly ash can replace a portion decreased in direct proportion to the amount of fly ash added to the of Portland cement in a concrete mix. Other SCMs, such as ground mix.86 granulated blast furnace (GGBF) slag and , are hydraulic, meaning that they react with water in the mix. Like fly ash, GGBF According to the American Concrete Institute (ACI), fly ash makes slag and silica fume are by-products of industrial manufacturing concrete less permeable, thereby reducing infiltration by water processes. SCMs can also include agricultural waste products, such and aggressive chemicals making concrete more long-lasting.87 as rice hull ash.80 In particular, fly ash increases concrete’s resistance to chemical attacks including alkali-silica and sulfate reactions, which Some SCMs, like fly ash, are also . ASTM standard can cause expansive cracking. Fly ash also makes concrete more C618 defines a pozzolan as a siliceous or siliceous and aluminous resistant to scaling from deicing salts.88 The decreased permeability material, which in itself possesses little or no cementitious value, is the result of additional cementitious compounds and reduced but, in finely divided form and in the presence of moisture it will water in the mix. This, in turn, reduces the chances for corrosion of chemically react with calcium hydroxide at ordinary temperatures to steel reinforcing, which is a major source of concrete failure. All this form compounds possessing cementing properties.81 In plain terms, improves the durability of concrete and increases the longevity of this means pozzolans are not cement, but they exhibit cement-like concrete. In other words, fly ash imparts properties that enhance the properties and can be used as an enhancement to concrete. performance of the concrete itself, extending its life and keeping the fly ash concrete from becoming construction debris for longer than a Fly ash is the most commonly standard concrete mix. Another performance benefit of fly ash is the mitigation of heat used pozzolan and is present in island effect. Since fly ash imparts a lighter color to concrete, it increases the albedo or reflectance of the surface when it is used in half the concrete poured in the exterior concrete flatwork. United States.82 Lessons Learned: If You Choose to Use Fly Ash in Concrete, What Are the Best When used in concrete, fly ash typically replaces between 15% to 35% of Portland cement in the mix with substitution ratios ranging Practices? between 1:1 and 1.5:1 (fly ash: Portland cement).83 Replacement rates exceeding 30% to 50% are considered “high-volume-fly- Based on our past project experiences, and discussions with ash-concrete” (HVFAC). However, definitions and thresholds for structural engineers, fabricators and suppliers, we will share the HVFAC appear to vary. The Federal Government, through the EPA’s following recommended applications for using or not using fly ash CPG recommends fly ash or other SCMs in the 20% to 30% in concrete. Many of these are echoed in the book Making Better replacement range. As stated earlier, these are recommendations not Concrete: Guidelines to Using Fly Ash for Higher Quality, Eco- requirements.84 Fly ash can also be incorporated into concrete in a friendly Structures by King, Bruce P.E. “blended cement,” in which fly ash is mixed with Portland cement and other cementitious materials, such as GGBF slag, natural pozzolans or silica fume.85 Performance of Concrete with Fly Ash

There is generally agreement on the performance benefits of adding fly ash to concrete. For example, fly ash increases the compressive strength of concrete. Some of these performance benefits also result in tangible environmental benefits. • • • • Avoid fly ash for composition noted above). which will nullify the accurate testing data about chemical issue of the aggregation of fly ash from multiple sources, Require proof of provenance of the fly ash (to avoid the of coal power plant. Specify flyashonlywhenaprojectiswithin50mileradius from one mine). chemical composition of coal does not generally vary greatly they generally burn coal from a single source mine and the chemical composition of their fly ash once a year because and by extension fly ash dealers, typically tested the for review and approval. (Please note that power plants, Require that chemical composition test data be submitted concrete. (SCM’s) derived from coal fired power plants used in mercury levels in supplemental cementitious materials ash in concrete or LEED™ for Healthcare’s limits on the Collaborative for High-Performance Schools (CHPS) for fly Comply with the mercury limit requirements of California’s Specification Requirements shown that fly ash can be corrosive to metals). or ductile iron pipes (as stated earlier, studies have – avoid using fly ash for concrete in contact with metal Below-grade concrete support structures for utility pipes the effect on color control and uniformity. Face mixes of architectural or – due to concrete when early strength is needed. Cold weather pours – may not be appropriate for fly ash to be removed quickly. Elevated beams and slabs – where formwork often needs • • • • Use fly ash for • Grouting of concrete block. requirements for high volume fly ash applications. curing period typically required to meet strength for some time after pouring. This allows for the 56-day Also building piles are often not loaded to full capacity well in water conditions due to decreased permeability. Drilled piers and piles – fly ash concrete can perform permanent formwork, so late set is less of a concern. application for fly ash because the metal deck acts as Lightweight concrete on metal deck – an ideal and poured footings in earth. Poured-in-place concrete walls and columns, mat slabs - - - yielded a range of responses: of the formwork. Conversations with several fabricators willingness to allow for early strength gain before removal application is dependent on the precaster’s ability and Precast concrete elements (with a few caveats) – this    Certain fabricators were reluctant to use fly ash, citing Typical range of 15 - 25% replacement for Portland Where precast units can be engineered with a face mix added manually to the mix). computer controlled whereas fly ash may need to be add cost and complicate the mix operations (which are of the mix (rheology is the study of the flow of matter), concerns that it would change the rheological behavior cement in the mix. insulated sandwich panels. for the backup mix or for the inner wythe of precast and a separate backup mix, fly ash is most appropriate 89

39 APPENDIX 40 APPENDIX

Summary of Current Regulations, groups include supporting the recycling of coal ash as a “safe, environmentally preferable alternative to disposal.”94 For the coal Codes and Technical Standards ash industry, recycling and beneficial use of fly ash are big business. To protect their interests, the “Citizens for Recycling First” group The current regulatory climate surrounding fly ash, combined with flooded the EPA with thousands of comments during the public the paucity of studies regarding its potential negative impacts, has review period, supporting the beneficial use of fly ash. According created a caveat emptor situation with little protection for the public to their website, the CEO of this organization is a past president of or guidance for architects, engineers, builders and owners. The the American Coal Council and former chairman of the Government ascendance of LEED™ in the last decade has codified fly ash in Relations Committee of the American Coal Ash Association.95 concrete as a fundamental process of the green building movement to the degree that it is virtually automatically specified on many Despite this reaction from the coal industry, some believe that the projects, often without scrutiny. first regulatory path is unlikely since the EPA would not want to relinquish its enforcement authority.96 Even some environmental Federal Regulations advocacy organizations have concerns about regulation under Subtitle C, the foremost being whether there is sufficient existing Historically, the disposal of coal combustion residual (CCR) materials capacity for landfilling if CCRs were to be designated as hazardous including fly ash has been exempt from federal regulations covering waste.97 As of the writing of this paper, the EPA has not updated hazardous waste, but in 1980 Congress ordered the EPA to study information on their website regarding the status of the proposed CCRs and to make a regulatory determination no later than 1983. rule. However, no regulations followed.90 In both 1993 and 2000, the EPA determined that CCRs did not warrant federal management as As an extension of its regulatory efforts, the EPA has conducted a hazardous waste.91 In 2010, for the first time, the EPA proposed facility assessments of existing coal ash impoundments throughout regulating fly ash. This was, in large part, a response to waste the United States. The assessment reports, which are posted on disposal accidents at fly ash surface impoundment facilities. The the EPA website, found that most of the facilities had a “high” most infamous of these spills occurred on December 22, 2008, at or “significant” hazard potential rating.98 Note that the ratings the Tennessee Valley Authority (TVA) plant in Kingston, Tennessee. were based on the potential for economic loss and damage to the A structural failure of one of the embankments of the pond caused environment and infrastructure if the impoundment were to fail more than one billion gallons of water and CCR waste to flood more (and not the structural stability of the impoundment itself). These than 300 acres, flowing into the Emory and Clinch Rivers.92 potential environmental and health impacts include leaching of contaminants and heavy metals into ground- and surface-waters as The EPA has proposed to regulate fly ash under the federal Resource well as the killing of aquatic life. Conservation and Recovery Act (RCRA). The proposed rule, for which several public hearings were conducted and public comments Separate from its regulatory role, the EPA encourages the use of solicited, will likely follow one of two possible paths: fly ash and other SCMs in concrete through its Comprehensive Procurement Guidelines (CPG), which designate items that must • Fly ash will be regulated under Subtitle C of the RCRA and will contain recycled content when purchased with appropriated be reclassified as “hazardous waste,” for which disposal would federal funds by government agencies (federal, state, or local) or fall under EPA enforcement. However, beneficial use of fly ash contractors. For cement and concrete, the CPG recommends, but in concrete, amongst other applications, will still be permitted does not require minimum levels of recycled content.99 under a “special waste” exemption. State and Local Regulations • Fly ash will be regulated under Subtitle D of the RCRA and would retain its current “non-hazardous” designation. Under this To our knowledge few state or local authorities have, or are scenario, disposal will be enforced by individual states, not by considering, rules to regulate the beneficial use of fly ash. the EPA. Furthermore, state regulations covering disposal are minimal, with only four states in the United States currently requiring all Some say that by opting for the first path, the EPA will stigmatize landfills to be monitored and only six states requiring all ponds fly ash as a hazardous material, potentially discouraging architects to be monitored for leaks.100 The vast majority of states do not and engineers from specifying it even though its beneficial use require liners to stop the migration of coal ash pollution into the would technically still be legal.93 This possibility has made the environment.101 Safeguards are also rare when it comes to coal ash industry nervous, leading to the formation of quasi-trade collection and dust controls at coal ash landfills and ponds.102 organizations with strong ties to industry. With seemingly innocuous names such as “Citizens for Recycling First,” the missions of these follows: under the LEED™ rating system). The voluntary criteria are as voluntary “Tiers” are akin to achieving higher certification levels 1 or Tier 2) above and beyond mandatory requirements. (These measures, which allow projects to achieve higher performance (Tier concrete, it does encourage its use as one of numerous voluntary While CalGreen does not explicitly require the use of fly ash in the state. commercial, hospital and school building construction throughout 1, 2011, is a uniform regulatory code covering all residential, gas reduction goals. CalGreen, which went into effect on January aimed at assisting the State of California in meeting its greenhouse statewide green building standards code in the United States United States. One example is CalGreen, the first mandatory have begun to find their way into building codes throughout the In the last few years, fly ash criteria (both mandatory and voluntary) Building Codes ash.” substances found in and other products made from coal is a severe lack of safeguards for public health in regards to harmful coal ash once it is reutilized and recycled into other products. There According to Greenpeace, “China lacks effective policy to monitor a greater risk. In China fly ash is almost virtually unregulated. and the disposal of coal by-products in landfills is considered behind this policy may be because there are few landfills in Holland materials that will become building materials. all fly ash to be diverted directly into building products or the raw and sensitivities of each country. For example, the Dutch require Fly ash regulations reflect the particular environmental concerns International regulations are too vast to cover in this paper in detail. International Regulations mercury controls for smokestack emissions. or , and unlike power plants, these kilns are exempt from manufacture Portland cement as a less expensive substitute for and wildlife. pollution, which had caused elevated mercury levels in nearby soil Ravena cement kiln, the state’s largest source of mercury air kilns throughout the state. 20-year old beneficial use designation for fly ash used at cement few to address these issues to some degree. In 2009, it revoked a supplies contaminated by coal ash. 137 locations have been documented by the EPA to have water groundwater, amongst other environmental impacts. Currently United States has unlined coal ash dumps that have contaminated Project (EIP), due to inadequate state regulations every region in the According to Eric Schaeffer, Director of the Environmental Integrity 108 109 105 The issue is that many cement kilns use fly ash to 104 This was in response to the LaFarge 103 New York State is one of the 106 107 The rationale ash in concrete). strength gain and delaying are some of the drawbacks of using fly formula, where high early strength concrete is required. (Delayed is also noteworthy that CalGreen allows exceptions to the above about twice as much fly ash as silica fume in a concrete mix. It “weighting” of materials. For example, the formula would allow In the equation above, no explanation is given as to the relative • • materials and products from buildings to guard against occupant Green GuideforHealthCare(GGHC), whichstrivestoeliminatetoxic Care may be because many of the credits are established by the One reason for the inclusion of mercury limits in LEED™ for Health credit.” incinerators does not qualify as a recycled-content materials for this mg/L). Fly ash generated as a by-product of plant wastes shall not have mercury content > 5.5 ppb (0.0055 “supplemental cementitious materials derived from coal fired power also recognizes that all fly ash is not equal in terms of toxicity: sourced materials (MR Credit 3), but unlike other LEED™ systems, like other LEED™ systems, rewards projects for using sustainably This omission is in contrast to LEED™ 2009 for Health Care, which potential toxicity levels of the fly ash. MR Credit 4.1, however, there are no criteria covering the type or LEED™ 2009, fly ash can contribute towards achievement of post-industrial recycled materials in a project. For example, under system, typically reward projects for incorporating fly ash and other Green building certification programs, such as the LEED™ rating Green Building Standards & Guidelines chemical resistant. not clear since fly ash, in general, is known to make concrete more materials by weight in the concrete mix. The basis of this criterion is applications, fly ash cannot exceed 25% of total cementitious cases where it may be exposed to deicing chemicals. of allowable fly ash (and other SCMs and pozzolans) in concrete in the New York City Construction Code (2008) limits the percentage include limitations on its use for certain applications. For example, While CalGreen encourages the use of fly ash, other building codes material in the concrete for each SCM. fume % / 12 = 1 Ground granulated blast furnace (GGBF) slag % / 50 + Silica SCM’s are combined within a concrete mix: A mix design equation is also provided for cases where multiple supplementary cementitious materials (SCMs) including fly ash. Non-residential projects: ash, slag or other materials. design by not less than 20% (Tier 1) or 25% (Tier 2), using fly Residential projects: 112 , where % is the percent of total cementitious reduce cement used in foundation mix use concrete manufactured with Fly ash % / 25 + 110 For these

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exposure. Several measures (MR Prerequisite 2, MR Credit 4.2 and acceptable level of strength development when used with hydraulic EQ Prerequisite 3) address hazardous materials, such as mercury. cement in concrete.115 In addition, MR Credit 3 (Sustainable Sourced Materials) will only permit fly ash with documentation that producing coal plants do Another standards-making body, the American Concrete Institute not co-fire with hazardous waste, medical waste, or tire-derived fuel (ACI), has expressed concern about the EPA’s proposed rule and that fly ash should not be generated from municipal solid waste described above. Designating fly ash as hazardous waste would incinerators.112 require rewriting standards and technical documents that currently address the use of fly ash in concrete including the following:116 Fly ash is also commonly addressed in voluntary design guidelines, like the California Collaborative for High Performance Schools ACI 232 - “Use of Fly Ash in Concrete.” This report gives an (CHPS), New York City’s High Performance Building Guidelines overview of the origin and properties of fly ash, its effect (HPBG) and High Performance Infrastructure Guidelines (HPIG). on the properties of hydraulic cement concrete and the Typically, these guidelines encourage the use of fly ash, but proper selection and use of fly ash in the production of focus more on benefits such as resource efficiency, durability hydraulic cement concrete and concrete products. and maintenance issues without regard for its potential health impacts. These standards recommend use of fly ash in common ACI 318 - “Building Code Requirements for Structural Concrete.” applications such as building enclosures (concrete and CMU) and A model concrete code, adopted and amended by state interior concrete floors. The NYC HPIG cites fly ash for less well- and municipal authorities for local building codes. known exterior uses such as impervious pavement, flowable fill for backfilling utility trenches and below-grade concrete support The technical standards above define the use of fly ash in concrete structures. (Please note for the latter, it is advisable to avoid using including maximum carbon content; however, they do not address fly ash for concrete in contact with metal or ductile iron pipes since potential toxicity of substances within the fly ash such as mercury. some studies have shown fly ash to be corrosive to metals).113 The In other words, they address only structural performance, not NYC HPIG also advocates using Portland cement due to its higher environmental performance. albedo properties in pavement. International Technical Standards Technical Standards Standards outside the United States for use of fly ash in concrete In the United States, specifications calling for fly ash in concrete vary greatly based upon region and country. In Canada, fly ash typically require compliance with two reference standards, ASTM specifications commonly cite Canadian standard CAN/CSA A23.5 – C618-08a and ASTM C311-07. These standards are also used “Canadian Specification for Supplementary Cementing Materials” outside of North America. and CAN/CSA A3001-08 – “Cementitious Materials for Use in Concrete.” These standards address various aspects of cementitious C618-08a is ASTM’s “Standard Specification for Coal Fly Ash materials such as the definitions, chemical, physical and uniformity and Raw or Calcined Natural Pozzolan for Use in Concrete.” requirements, required tests, procedures for inspection and According to ASTM, “this specification covers coal fly ash and raw sampling, units of measurement, packaging, and marking and or calcined natural pozzolan for use in concrete where cementitious storage. or pozzolanic action or both is desired or where other properties normally attributed to fly ash or pozzolans may be desired or where In Europe, the primary technical standard is BS EN 450 – both objectives are to be achieved.” The specification tests materials “European Standard for Fly Ash.” This is a harmonized European for “fineness, strength activity index, water requirement, soundness standard for fly ash that replaces the former British Standard and autoclave expansion or contraction.”114 BS 3892 Part 1. The standard alternatively refers to fly ash as “Pulverized Fuel Ash” (PFA), which is the by-product of coal ASTM C311-07 is the “Standard Test Methods for Sampling and combustion at power stations and appears to be the equivalent Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement of what we commonly know as fly ash.117 BS EN 450 provides Concrete.” This standard covers “procedures for sampling and performance criteria for fly ash, such as loss of ignition, fineness, testing fly ash and raw or calcined pozzolans for use as a mineral particle density and percent of chlorides. It is important to note admixture in Portland-cement concrete.” These chemical analyses that standards development in Europe has been influenced by include moisture content, available alkali, iron oxide, and silicon the primary trade organization for European energy producers, dioxide amongst other things and physical tests include density, the European Coal Combustion Products Association (ECOBA), fineness and water requirement. The strength test is specifically which appears to be analogous to the ACAA in the United States. used to determine whether fly ash or natural pozzolan results in an According to its website (www.ecoba.com), ECOBA was founded in begun to address these public health issues. as LEED™ for Health Care and Green Guide for Health Care have uncertainty and confusion. Only recently, progressive guidelines such and owners. Furthermore, the current regulatory climate has created and little guidance for architects, designers, specifiers, builders, concerns surrounding fly ash providing little protection for the public building product standards. Many of these do not address the health ash have been written into codes, design guidelines and other To summarize, in recent years, criteria relating to the use of fly materials from coal. 1990 to deal with matters related to the usage of construction raw

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Body Burden of Substances in Fly Ash via Government Watch List

Known Health Effects

Suspected Health Effects Health Effects

Substances Asthma Trigger Asthmagen Asthmagen Sensitizer Cardiovascular or Blood Toxicant Developmental Toxicant Endocrine Toxicant Gastrointestinal or Liver Toxicant Hazardous Air Pollutant Immunotoxicant Kidney Toxicant Musculoskeletal Toxicant Neurotoxicant Persistent Bioaccumulative Chemical Toxic Reproductive Toxicant Respiratory Toxicant Respiratory Sensitizer Skin or Sense Organ Toxicant Aluminum / 7429-90-5 k k k s s Antimony / 7440-36-0 s s s s s Arsenic / 7440-38-2 k s k s s s / 7440-39-3 s s s s s Beryllium / 7440-41-7 s k s s s s s s s Boron / 7440-42-8 s s s s s Cadmium 7440-43-9 s k s k s s s s k k s Calcium / 7440-70-2 (VI) / 7440-47-3 k k k s k Chloride (Chlorine) / 7782-50-5) Chloride is more than one chlorine attached k k s s s s s s Cobalt / 7440-48-4 k k k k s s s s s s s k s / 7440-50-8 s s s s s s Fluoride / 16984-48-8 s s s k s Iron / 7439-89-6 s s s s s s s Lead / 7439-92-1 k s k s s s s s k s s / 7439-93-2 s s Magnesium / 7439-95-4 s s Managanese / 7439-96-5 s s k s s Mercury / 7439-97-6 s k s s s s k k s s s Molybdenum / 7439-98-7 s s s Nickel / 7440-02-0 k k k s s s s s s s s Nitrate / 14797-55-8 s s s Phosphorus / 7723-14-0 s s k s s k s s s Potassium / 7440-09-7 Selenium / 7782-49-2 s s s s s s s s s s Silver / 7440-22-4 s s s s Sodium / 7440-23-5 Strontium / 7440-24-6 s Sulfate / 18785-72-3 Sulphide Thallium / 7440-28-0 s s s s s s Tin / 7440-31-5 s s s s s s Titanium / 7440-32-6 s s Vanadium / 7440-62-2 k s s s s / 7440-66-6 s s s s s s Coal Combustion Wastes in Our Lives Scaffolding, non-catastrophic failure Doors Marine pilings Roofing tiles and panels Drywall Highway sound barriers Railway sleepers Utility poles and crossarms Recycled plastic lumber Blasting grit Road base / sub-base Acoustical ceiling tile Paints and undercoatings Roofing shingles Cinder block Grout Soil modification & stabilization Aggregate Fireplace mantles House siding and trim Structural insulated housing panels Wood-like decking Slate-like roof tiles Asphalt roads Flowable fill Flooring and ceiling tile Binding agent Carpet backing Roofing granules Cement replacement (in concrete) Raw feed for (in kiln) Synthetic gypsum Construction and Building Materials Flotation devices Bowling balls Running tracks Driveways Auto bodies and boat hulls Dog houses Carpet backing Picture frames Utensils and tool handles Tooth­paste Kitchen counter tops Consumer Products and Home Uses source: http://www.peer.org/campaigns/publichealth/coalash/everywhere.php Snow and ice traction on roads and parking lots Mining applications / minefill Structural fills and embankments Land contour and golf course fill Dumping on rivers to melt ice Loose Application on Roads, Rivers, and as Fill Recycled drywall soil amendment – stock feed yards Agricultural stakes Cattle feeders Dairy feedlot pads Soil amendment and fertilizer Agriculture Artificial reef Mail boxes Molding Pallet blocks Planters Landscape timbers Park benches Garage doors Shower stalls Paints and plastics filler Paving stones Vinyl flooring PVC pipe Bricks Rail road ties Columns Architectural interiors and exteriors Crypts Sign posts Window frames

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Portland Cement vs. Fly Ash Comparison Chart

PORTLAND CEMENT FLY ASH

PRO CON PRO CON

CONCRETE CONCRETE CONCRETE CONCRETE • In some applications • Energy use and fuel • Improves strength, segregation, and • Concerns about freeze/thaw concrete takes less combustion during mining ease of pumping of the concrete performance and a tendency time to cure operations result in to effloresce, especially atmospheric emissions, • Improved workability means less when used as a complete

like carbon dioxide (CO2) water is needed resulting in less replacement for Portland as well as numerous other segregation of the mixture and less cement pollutants. likelihood of cracking • Concrete mix is essentially • Great deal of energy to • Fly ash itself is less dense than a big chemical reaction, grind up, heat in a kiln and Portland cement, but the produced adding fly ash slows the process into the final product concrete is denser, less permeable, curing of the concrete and results in a smoother surface • Higher embodied energy with sharper detail RAW MATERIAL

RAW MATERIAL • Lower embodied energy (when • Energy use and fuel coal extraction is not included and combustion during coal • Water pollution from sourced within 30 miles of the site) mining operations result in mining runoff can cause atmospheric emissions deoxygenation • Can be formulated to produce various set times, cold weather • Contains approximately 1 • Impact from mining can resistances, strengths and strength part per million of mercury be significant in terms gains, depending on the job without and other heavy metals of habitat alteration and additional additives destruction and soil erosion • Acid rain and greenhouse gases • Cost effective compared to Portland from the burning of coal • Great deal of energy to mine cement out of the Earth • Improves the performance and quality of the concrete

• Contains alumina and silica, which strengthens cement

• Makes concrete more resistant to chemical attacks (sulphates and alkali-aggregate reaction), which protects against corrosion of reinforcing steel

RAW MATERIAL

• Industrial by-product of coal that is otherwise waste Graphics Index Electricity ProductionbyCoalintheU.S.andCanada13 Known CoalReservesintheU.S.andCanada12 Portland Cementvs.FlyAshComparison Chart46 Body BurdenofSubstancesinFly AshviaGovernmentWatch List 44 Exxon Valdez OilSpillvs.TVA’s KingstonPower PlantCoalAshPondLeveeBreak34-35 Greenhouse Gas(GHG)Emissions31 Waste DisposalVolume 27 Is ThereFlyAshinThisRoom?22-23 Coal FueledPowerPlantProcess21 Magnified View ofClassFFlyAsh19 Chemical Make-UpofFlyAsh19 Dependence onCoalforElectricitybyCountry18 Life CycleofFlyAsh14-15

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Glossary of Terms

Cementitious – Having the characteristics of cement.

Coal Combustion Residue (CCR) – The coal that is not incinerated during power generation, which includes fly ash, bottom ash, boiler slag, and flue gas desulfurization material.

Class C Fly Ash – A category of fly ash by the American Society for Testing and Materials (ASTM) under their C618 standard. This class of fly ash has pozzolanic as well as cementitious properties and is produced from burning lignite or subbituminous coal. Type C fly ash has the following chemical properties:

Silicon dioxide (SiO2) + aluminum oxide (Al2O3) + iron oxide (Fe2O3) 50.0 min. %

Sulfur trioxide (SO3) 5.0 max. % Moisture content 3.0 max. % Loss on ignition 6.0 max. %

Class F Fly Ash – A category of fly ash by the American Society for Testing and Materials (ASTM) under their C618 standard. This class of fly ash has pozzolanic properties and is produced from burning anthracite or bituminous coal. Type F fly ash has the following chemical properties:

Silicon dioxide (SiO2) + aluminum oxide (Al2O3) + iron oxide (Fe2O3) 70.0 min, %

Sulfur trioxide (SO3) 5.0 max. % Moisture content 3.0 max. % Loss on ignition 6.0 max. % * * Note: according to the ASTM, the use of Class F pozzolan containing up to 12.0 % loss on ignition may be approved by the user if either acceptable performance records or laboratory test results are made available.

Flue Gas Desulfurization (FGD) – is a technology that removes sulfur dioxide (SO2) from the flue gases of power plants.

Fly Ash – The fine particulate waste gathered from the flue gases during coal combustion, smelting, or waste . For the purposes of this paper the term fly ash is only referring to ash from coal combustion.

Greenhouse Gases (GHG) – Greenhouse gases are naturally occurring as well as the result of human activities. Water vapor, carbon dioxide, methane, nitrous oxide, and ozone all are GHG found in nature. Human activities add to the levels of the naturally occurring gases: carbon dioxide is released to the atmosphere from solid waste, fossil fuels (oil, natural gas, and coal), and wood and wood products are burned; methane is emitted during the production and transport of coal, natural gas, and oil; methane is also released from the decomposition of organic wastes in solid waste landfills, from livestock; nitrous oxide is emitted during agricultural and industrial activities, as well as during combustion of solid waste and fossil fuels. Other human activities release powerful greenhouse gases that are not found in nature; some of these gases are: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), all of which are generated from industrial processes.118

Ground Granulated Blast Furnace Slag (GGBFS) – GGBFS is the non-metallic by-product of iron ore being smelted into pig iron in a blast furnace. This slag material is ground up into a powder and used as cementitious material in concrete.

High-volume-fly-ash-concrete (HVFAC) – A concrete mix that contains more than 50% fly ash by mass of the cementitious material.

Portland cement – A hydraulic cement is created when a mixture of limestone and clay are heated in a kiln and then pulverized. The name Portland originally was a reference to the stone quarried on the Isle of Portland, which has a color similar, but now is the universal name for this type of hydraulic cement.

Pozzolan – Is a material that when combined with calcium hydroxide has cementitious properties. The most common use of pozzolans is as an addition to or in lieu of Portland cement in concrete.

Silica Fume – Is a pozzolan material that is the by-product of manufacture of silicon or ferro-silicon metal.

Supplementary Cementitious Materials (SCM) – Is a material that reacts with substances in the concrete mix to form cement-like compounds. Your Home Planet United States Green Building Council United States Environmental Protection Agency Union of Concerned Scientists Public Employees for Environmental Responsibility Portland Cement Association Pew Center on Global Climate Change Perkins+Will’s Precautionary List Healthy Building Network Headwater Resources Green Source Greenpeace Environmental Building News Earth Justice Citizens for Recycling First Building Green American Society for Testing and Materials American Coal Council American Coal Ash Association General Web Resources ...... www.greenpeace.org www.ebn.com www.earthjustice.org www.recyclingfirst.org www.buildinggreen.com www.astm.org www.americancoalcouncil.org www.acaa-usa.org www.yourhomeplanet.com www.usgbc.org www.epa.gov www.ucsusa.org www.peer.org www.cement.org www.pewclimate.org www.transparency.perkinswill.com www.healthybuilding.net www.flyash.com www.greensource.construction.com

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30 Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Endnotes Significance, U.S. Geological Survey Fact Sheet FS-163-97; October, 1997.

1 “INCREASING UTILIZATION: What Can We Do?” Fly Ash. Headwater Resources. Web. 31 Mara Hvistendahl, Coal Ash Is More Radioactive than Nuclear Waste, By burning away 25 Sept. 2011. . all the pesky carbon and other impurities, coal power plants produce heaps of radiation; Scientific American, December 13, 2007. 2 Elko, Tom. “Green enough for 35W concrete, toxic coal ash is also used on farms” Minnesota Independent News, April 3, 2009. 32 U.S. Geological Survey (USGS), Fact Sheet FS-163-97 “Radioactive Elements in Coal and Fly Ash,” (Oct. 1997). 3 Post, Nadine M. “Fly Ash Looms As The ‘New Asbestos’ - Green Building News -- Environmental Building News - Green Source. Web. 25 Sept. 2011. . Rule. http://peer.org/docs/epa/8_18_10_PEER_Comments_CoalAsh_Rule.pdf, August 18, 2010, p. 1. 4 “Docket Number EPA-HQ-RCRA-2009-0640, Notice of Proposed Rule for.” 18 Aug. 2010. Web. 25 Sept. 2011. . p. 14. Mercury Levels in Coal Ash Pose New Risks,” August 2010.

5 Union of Concerned Scientist: How Coal Works http://www.ucsusa.org/clean_energy/ 35 “A Life Cycle Comparison of Disposal and Beneficial Use of Coal Combustion Products coalvswind/brief_coal.html. in Florida (Part 1),” by C. Babbitt and A. Lindner, Univ. of Florida, Gainesville, FL (2008), p. 202. 6 “Materials Characterization Paper - in Support of Proposed Rulemaking,” from the EPA website, Wastes – Non Hazardous Waste, April 5, 2010. 36 Environmental Building News (EBN), “Coal Ash in Spill Could Not Have Been Used in Concrete,” December 30, 2008. 7 “Out of Control: Mounting Damages From Coal Ash Waste Sites.” February 2010 report by Environmental Integrity Project and Earthjustice. 37 “A Life Cycle Comparison of Disposal and Beneficial Use of Coal Combustion Products in Florida (Part 1),” by C. Babbitt and A. Lindner, Univ. of Florida, Gainesville, FL, 8 “Reducing Environmental Impacts of Cement and Concrete,” p. 11. EBN, vol. 19, no. 2008, p. 202. 9, Sept. 2010 38 “Analysis of fly ash heavy metal content and disposal in three thermal power plants 9 Hanle, Lisa. “CO2 Emissions Profile of the U.S. Cement Industry,” U.S. Environmental in India.” by S. Sushil, V. Batra, Center for Energy & Environment, TERI School of Protection Agency, 2002. Advanced Studies, New Delhi, India. Published by Elsevier Ltd., 2006, p. 1.

10 These are a common cited percentages, but we could not find the original source of this 39 U.S. EPA website: Wastes – Non Hazardous Waste – Industrial Waste. “Frequent information. Questions.” http://www.epa.gov/wastes/nonhaz/industrial/special/fossil/coalash-faqs. htm#3. 11 Intergovernmental Panel on Climate Change (IPCC), Working Group II, p. 661. Web. 29 Sept. 2011. . 41 “U.S. Environmental Protection Agency Action Memorandum (AM) Fact Sheet on Selected Engineering Evaluation/Cost Analysis (EE/CA) Alternative Kingston Fossil 13 “EcoSmart™ Concrete - The Facts - What Is It?” EcoSmart Concrete - Home. Web. 30 Fuel Plant Release Site.” Web. 30 Sept. 2011. . FINAL_TVA_EECA_Fact_Sheet051810.pdf>.

14 Some of the other green building systems that recognize fly ash as recycled content are: 42 Greenpeace “The true cost of Coal: An investigation into Coal Ash in China,” September Breeam, Casbee, Estidama, Greenstar, and GreenGlobes. 2010.

15 Johnson, Jeffrey W. “The Foul Side of ‘Clean Coal’,” Chemical & Engineering News, 43 Lee Ann Paradise, David Petechuk, Leslie Mertz. Science in Dispute, Volume 2 (2003) February 23, 2009. 44 Bill Walsh, Fly Ash in Building Products: Proceed with Precaution, Healthy Building 16 Walsh, Bill. “Fly Ash In Building Products: Proceed With Caution,” Healthy Building Network Newsletter, September 15, 2010. Network, September 15, 2010. 45 Fly Ash Contributes to Sustainable Concrete Construction. 2010. http://www.concrete. 17 “Key World Energy Statistics 2009,” International Energy Agency, 2009, p. 25. org/education/webcasts/PDFs/2010_Xtreme_Concrete_123_Forum_Fly_Ash.pdf.

18 Existing Electric Generating Units in the United States, 2005,” Energy Information 46 http://www.house.gov/smbiz/hearings/hearing-07-22-10-coal-combustion/Adams.pdf. Administration website, accessed April 2008. 47 America’s Power. Web. Residuals.” http://www.epa.gov/wastes/nonhaz/industrial/special/fossil/coalashletter.htm. 48 Enduring Communities. http://www.enduringcommunities.org/sustainapedia/blog. 20 Environmental Building News (EBN), “Coal Ash in Spill Could Not Have Been Used in php/?tag=environmental-protection-agency. Concrete,” December 30, 2008. 49 “Public Employees for Environmental Responsibility: News Releases.” Public Employees 21 Johnson, Jeffrey W. “The Foul Side of ‘Clean Coal’,” Chemical & Engineering News, for Environmental Responsibility: Homepage. Web. 30 Sept. 2011. .

22 IEA. Key World Energy Statistics 2010. 50 “Green House Gas Emissions due to Concrete Manufacture,” by D. Flower and J. Sanjayan, Monash University, Clayton, Australia, 2007, p. 282. 23 Goodell, Jeff, Big Coal: The Dirty Secret Behind America’s Energy Future, Houghton Mifflin Company,2007, New York, NY. Page 143 51 “Concrete CO2 Fact Sheet” prepared by National Ready Mixed Concrete Association (NRMCA), June 2008, . Combustion Wastes,” National Research Council of the National Academies, 2006. 52 EBN, vol. 19, no. 9, Sept. 2010. “Reducing Environmental Impacts of Cement and 25 “Human and Ecological Risk Assessment of Coal Combustion Wastes,” RTI, Research Concrete,” p. 11. Triangle Park, August 6, 2007, prepared for the U.S. Environmental Protection Agency. 53 “Green House Gas Emissions due to Concrete Manufacture,” by D. Flower and J. 26 Perkins+Will’s Precautionary List. www.transparency.perkinswill.com Sanjayan, Monash University, Clayton, Australia (2007), p. 282.

27 Perkins+Will’s Precautionary List. www.transparency.perkinswill.com 54 GreenSource magazine, “Fly Ash Looms As The’New Asbestos’” (4/15/2010). (article originally appeared on www.enr.com). 28 “All You Need to Know about Fly-ash | Building Green TV.” Home | Building Green TV. Web. 30 Sept. 2011. . from the Portland Cement Manufacturing Industry” prepared for U.S. Environmental Protection Agency Office of Air Quality Planning and Standards (OAQPS) Air Benefit and 29 Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Cost Group By RTI International, April 2009. Significance, U.S. Geological Survey Fact Sheet FS-163-97; October, 1997. 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56

Quality, Eco-friendly Structures, Green Building Press, 2005, p. ? King, Bruce P.E., Making better Concrete: Guidelines to using Fly Ash for Higher Quality, Eco-friendly Structures, Green Building Press, 2005, p. 3 King, Bruce P.E., Making better Concrete: Guidelines to using Fly Ash for Higher Concrete,” p. 12. EBN, vol. 19, no. 9, Sept. 2010. “Reducing Environmental Impacts of Cement and Concrete,” p. 12. EBN, vol. 19, no. 9, Sept. 2010. “Reducing Environmental Impacts of Cement and by Environmental Integrity Project and Earthjustice. “Out of Control: Mounting Damages From Coal Ash Waste Sites.” February 2010 report report by Greenpeace. “The true cost of Coal: An investigation into Coal Ash in China,” September 2010 http://www.healthybuilding.net/news/100519fly-ash-epa.html. 19, Number 9, Septmeber 2010. ash from coal power plants a safe substitute?, Environmental Building News; Volume carbon emissions of concrete means replacing its Portland cement content. But is fly Brent Ehrlich, Reducing Environmental Impacts of Cement and Concrete Reducing the http://www.buildinggreen.com/live/index.cfm/2010/9/14/Future-Concrete-Research. http://cee.mit.edu/news/releases/2009/cementDNA. Solidified Fly Ash. Cement and Concrete Research. Volume 35, March 2004. Yu et All, The Leachability of Heavy Metals in Hardened Fly Ash Cement and Cement Solidified Fly Ash. Cement and Concrete Research. Volume 35, March 2004. Yu et All, The Leachability of Heavy Metals in Hardened Fly Ash Cement and Cement Solidified Fly Ash. Cement and Concrete Research. Volume 35, March 2004. Yu et All, The Leachability of Heavy Metals in Hardened Fly Ash Cement and Cement Fuels, 2009, 23 (4), p. 2035–2040. Properties and Mercury Sorbent Affect Mercury Release from Curing Concrete.” Energy Danold W. Golightly, Chin-Min Cheng, Linda K. Weavers, Harold W. Walker; “Fly Ash 2008, 22 (5), p. 3089–3095. of Aerated That Contain Fly Ash and Activated Carbon Sorbent” Energy Fuels, Panuwat Taerakul and William E. Wolfe; “Gaseous Mercury Release during Steam Curing Danold W. Golightly, Chin-Min Cheng, Ping Sun, Linda K. Weavers, Harold W. Walker, Science and Technology, Rome, October 8, 1997, p. 27-48. Materials;” Proceedings of Mario Collepardi Symposium on Advances in Concrete P. Schiessl, I.Hohberg, “Environmental Compatibility of Cement-Based Building 19, Number 9, September 2010. ash from coal power plants a safe substitute?, Environmental Building News; Volume carbon emissions of concrete means replacing its Portland cement content. But is fly Brent Ehrlich, Reducing Environmental Impacts of Cement and Concrete Reducing the Health Facts on Fly Ash Constituents. http://aahealth.org/App_pdfs/Fly_ash2.pdf. Michel de Spot of the EcoSmart in email to Perkins+WIll Vancouver. (2008), p. 204, 208. in Florida (Part 1),” by C. Babbitt and A. Lindner, Univ. of Florida, Gainesville, FL “A Life Cycle Comparison of Disposal and Beneficial Use of Coal Combustion Products Source), Energy. “Existing U.S. Coal Plants.” SourceWatch. Web. 30 Sept. 2011. html. Union of Concerned Scientists. http://www.ucsusa.org/clean_energy/coalvswind/c02a. Environmental Integrity Project and Earthjustice by Eric Schaeffer, November 16, 2010. “Re-evaluation of Estimates in USEPA Regulatory Impact Analysis” prepared for the http://earthjustice.org/news/press/2010/epa-coal-ash-analysis-flawed based upon org/news/news_id.php?row_id=1382> for Environmental Responsibility: Homepage. Web. 30 Sept. 2011. Business. Web. 30 Sept. 2011. “Common Dreams NewsWire.” Home | Common Dreams. Web. 30 Sept. 2011.

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51 APPENDIX 52 APPENDIX

110 New York City Construction Code (2008 version), Chapter 19 – Concrete, Article 1904.2.3, p. 405.

111 LEED™ 2009 for Health Care (Nov. 2010), US Green Building Council, p. 58.

112 Green Guide for Health Care, version 2.2 (Jan. 2007), p. 9-32.

113 New York City High Performance Infrastructure Guidelines (HPIG), NYC Dept. of Design & Construction and Design Trust for Public Space, October, 2005, p. 100, 107.

114 ASTM Standard Guide: http://www.astm.org/Standards/C618.htm.

115 Fluorescence, X-Ray. “ASTM C311 - 11a Standard Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland Cement Concrete.” ASTM International - Standards Worldwide. Web. 30 Sept. 2011.

116 “Fly Ash Looms as the New Asbestos,” by N. Post, Green Source Magazine (April 15, 2010), Article originally appeared on www.enr.com, available at: http://greensource. construction.com/news/2010/100415Fly_ash-1.asp.

117 “BS EN 450 Fly Ash: Sustainable Solutions for Construction Specialists,” a publication of ScotAsh Limited, Kincardine, Scotland. Available at: www.scotash.com/pdfs/ newBSEN450.pdf.

118 “EcoLodgical - Green Hotel Environmental Design, Operation and Management Tool.” YourHomePlanet = Environmental Design and Green Building Construction Portal. Web. 30 Sept. 2011. www.perkinswill.com